Program features 167
Autophasing for permanent magnet synchronous motors
Note: Autophasing must be performed before the lift is in operation. Otherwise
uncontrolled movement of the lift can occur.
Autophasing is an automatic measurement routine to determine the angular position
of the magnetic flux of a permanent magnet synchronous motor. The angular position
of the magnetic flux is required to control the motor torque accurately.
Sensors like absolute encoders and resolvers indicate the position of the magnetic
flux at all times after autophasing is performed. A standard pulse encoder determines
the rotor position only when it rotates. This requires a new autophasing at every
power-up.
Note: Autophasing is not required if the angle of magnetic flux is known and/or stored
in the encoder memory (EnDat or Hiperface).
• If the angle is known, example, marked to motor name plate, it can be set
manually with parameter 97.17 POS OFFSET USER. It is also needed to set
parameters 97.01 USE GIVEN PARAMS = UserPosOffs and 99.12 POS OFFSET
SRC = Drive mem.
• If the angle offset is stored in the encoder memory, it can be read by setting
parameter 99.12 POS OFFSET SRC = Encoder mem. The reading from encoder
must be triggered by selecting the parameter 90.06 ENC PAR REFRESH.
Autophasing is performed with permanent magnet synchronous motors in the
following cases:
• One-time measurement when an absolute encoder or resolver is used
• At every power-up when an incremental encoder is used
N
S
Rotor
Absolute encoder/resolver
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